Queen Elizabeth II's granddaughter Zara Phillips has given birth to a baby girl, Buckingham Palace says.
The child is 16th in line to the British throne.
The baby was born at Gloucestershire Royal Hospital in western England and weighed 3.5 kilograms. The palace said her name would be released "in due course".
This is the first child for Phillips and her husband, rugby player Mike Tindall, and a fourth great-grandchild for the queen. The palace said Tindall was present at the birth.
In a statement, the palace said the Queen, her husband Prince Philip and the baby's grandparents "are delighted with the news".
The 32-year-old Phillips, an equestrian who won a silver medal at the 2012 Olympics, is the daughter of the Queen's daughter Princess Anne and Captain Mark Phillips.
She was expected to return to competitive horse riding following the birth, as she hoped to enter the Badminton Horse Trials in May, and the World Equestrian Games in France in August.
The Queen's other great-grandchildren were 6-month-old Prince George, son of Prince William and his wife Catherine; and the two daughters of Zara's brother Peter Phillips and his wife Autumn.
Tindall today tweeted about the news, saying the birth of his daughter made for "best day of [his] life".
It seems the new father has settled down since his cavorting behaviour in New Zealand in 2011 made tabloid headlines around the world.
While partying in Queenstown with his Rugby World Cup team, Tindall was filmed flirting with a young woman.
Zara jetted to New Zealand to meet her husband, and later brushed the mystery woman off as an old friend.